This invention relates to token ring local area networks, and more particularly to a means for diagnosing the integrity of a particular hardware component without connecting the component into the network.
One local area network ("LAN") architecture is the Token Ring topology local area network at 4- and 16-Mbit/second. IEEE 802.5 is an IEEE local area network standard that closely follows the token ring standard, and currently supports 4-Mbit/second token ring networks. IEEE 802.5 is described in "Token Ring Access Method and Physical Layer Specifications," ISBN 1-55937-012-2, IEEE Std. 802.5-1989 (ANSI), IEEE, 345 E. 47th Street, New York, N.Y. 11017. Token ring and IEEE 802.5 topologies connect computer systems in a local environment.
In order to test hardware components connected into a token ring or IEEE 802.5 LAN, one must also consider lobe cables connecting the components, other devices on the ring, and the risk of degrading the network performance while performing the testing. It has been necessary in the past to supply a "known good" lobe cable and a "known good"0 Token Ring Multi-Station Access Unit (MsAU) with no other nodes attached to achieve adequate troubleshooting capability. The MsAu is a passive device which includes a relay set, and receives power to operate the relays from node devices inserted into the ring.
It would therefore represent an advance in the art to provide a means for diagnosing the integrity of a particular hardware component for a token ring LAN without connecting the component into the network.